Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a display screen or portion thereof withtransitional graphical user interface, showing a first image in asequence, showing our new design;

FIG. 2 is a front view showing a second image thereof;

FIG. 3 is a front view showing a third image thereof;

FIG. 4 is a front view showing a fourth image thereof; and,

FIG. 5 is a front view showing a fifth image thereof.

The outermost broken lines illustrating portions of a display screen orportion thereof form no part of the claimed design. The remainder of thebroken lines illustrating portions of the Transitional Graphical UserInterface forms no part of the claimed design. The contrast shown ingrayscale in the figures represents a contrast of appearance.

The appearance of the transitional graphical user interface sequentiallytransitions between the images shown in FIGS. 1-5. The process or periodin which one image transitions to another image forms no part of theclaimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.